root/sysproc.c

DEFINITIONS

1. sys_fork
2. sys_exit
3. sys_wait
4. sys_kill
5. sys_getpid
6. sys_sbrk
7. sys_sleep
8. sys_uptime

   1 #include "types.h"
   2 #include "x86.h"
   3 #include "defs.h"
   4 #include "date.h"
   5 #include "param.h"
   6 #include "memlayout.h"
   7 #include "mmu.h"
   8 #include "proc.h"
  10 int
sys_fork(void)
  12 {
  13   return fork();
  14 }
  16 int
sys_exit(void)
  18 {
exit();
  20   return 0;  // not reached
  21 }
  23 int
sys_wait(void)
  25 {
  26   return wait();
  27 }
  29 int
sys_kill(void)
  31 {
  32   int pid;
  34   if(argint(0, &pid) < 0)
  35     return -1;
  36   return kill(pid);
  37 }
  39 int
sys_getpid(void)
  41 {
  42   return proc->pid;
  43 }
  45 int
sys_sbrk(void)
  47 {
  48   int addr;
  49   int n;
  51   if(argint(0, &n) < 0)
  52     return -1;
addr = proc->sz;
  54   if(growproc(n) < 0)
  55     return -1;
  56   return addr;
  57 }
  59 int
sys_sleep(void)
  61 {
  62   int n;
uint ticks0;
  65   if(argint(0, &n) < 0)
  66     return -1;
acquire(&tickslock);
ticks0 = ticks;
  69   while(ticks - ticks0 < n){
  70     if(proc->killed){
release(&tickslock);
  72       return -1;
  73     }
sleep(&ticks, &tickslock);
  75   }
release(&tickslock);
  77   return 0;
  78 }
  80 // return how many clock tick interrupts have occurred
  81 // since start.
  82 int
sys_uptime(void)
  84 {
uint xticks;
acquire(&tickslock);
xticks = ticks;
release(&tickslock);
  90   return xticks;
  91 }